OVERHEATING

Buick Other

1990 buick lasaber custom, car is overheating, checked water pump, fine, thermostat, fine, rad is not cloged, runs fine but overheats, ther is no water circulation, observed several times, thats y I checked pump and thermostat, no white steam from exhaust, no loss of coolant only due to overheating, any other reason? Please respond :